Cita APA (7th ed.)

Soars John & Soars Liz. (2001). Headway: Workbook with Key. Oxford, Oxford University Press, 2001.

Cita Chicago (17th ed.)

Soars John i Soars Liz. Headway: Workbook with Key. Oxford, Oxford University Press, 2001, 2001.

Cita MLA (9th ed.)

Soars John i Soars Liz. Headway: Workbook with Key. Oxford, Oxford University Press, 2001, 2001.